In its latest update to its S-1 filing, Twitter announced that it will be raising the price range for its public offering from $17-20 up to $23-25. That would allow Twitter to raise around $1.75 billion and value the company around $14 billion, up from $10.9 billion. The upgrade indicates that Twitter found strong demand during its investor roadshow, but it has also been conservative all along about its pricing, and many analysts expected this move. The company still has a little time to fine tune its offering, and is expected to finalize the price on Wednesday and go live Thursday morning.

The updated documents also revealed patent infringement claims filed against Twitter. "We recently received a letter from International Business Machines Corporation, or IBM, alleging that we infringe on at least three US patents held by IBM, and inviting us to negotiate a business resolution of the allegations." This kind of patent shakedown is common before an IPO: Yahoo squeezed millions of pre-IPO shares out of Google with this tactic, and tried the same with Facebook last year. There's no word yet on how much IBM is asking to settle the complaint.